Two Red Wires and One Yellow Wire

Hi,

I'm brand new to this and am trying to install the Lutron Occupancy Sensing Switch, which has one green, two black and a bare wire.

Can anyone tell me what I'm looking at here? Why does it look like there two red wires connected to the bottom? From watching youtube videos, it looks like perhaps there is an outlet connected to it but it doesn't seem so to me.

My best guess right now is to hook up the two red wires to one black wire on the new switch, the yellow to the other black wire on the new switch, then the green and bare wire on the switch together. Is that correct? I live in Chicago if that info is relevant.

Attachment 840